Are you genuinely required to confess a forgotten sin?

My wife and I have returned to the church after a year away. Parenthood and laziness allowed us to build a habit of missing church, until eventually we had no relationship to our faith.We are running headfirst back in, and just had our first confession in a year. Obviously a lot happens in a year, and we each did a full examination of conscience before going to confession, keeping a note on our phones.Of course our phones died and we had the pressure of a long line behind us, then the priest hurried us along as well in each of our respective confessions.Going over how we felt after and the joy of finally being clean, we realized each of us had forgotten a couple of grave sins. We made full contrite confessions, with every intention to confess all our sins, but in the moment genuinely forgot.I started looking online but there is nothing but contradictions. I wanted to be sure our confession wasn’t invalid, but instead found people saying it was valid, but the remembered sins MUST be confessed. That seems to be a direct theological contradiction. Either our sins are forgiven and forgotten or they are not. It doesn’t seem possible to have the grace or confession and yet still have the God separating mark of mortal sin.Any priests here who could help out?